Flow controller



N. BREW-ER FLOW CONTROLLER Dec. 31, 1963 2 Sheets-Sheet 1 Filed Oct. 11,1954 fldww 5 E LF ACTUATED FLOW CONTROLLER flow) P .w n M F wiz W m M WY0 B Z a 1m 9 l m z #m N. BREWER FLOW CONTROLLER Dec. 31, 1963 2Sheets-Sheet 2 Filed Oct. 11, 1954 1 a @Qx A i m g V. .f may fi j 6 7 6A l R T005249 IN VEN TOR. I144 7/144/Y/[Z EP'WE/f' BY i ATTU/P/VEXUnited States Patent 3,115,892 FLOW CONTROLLER Nathaniel Brewer,Newtown, Pa, assignor to Fischer & Porter Company, Hatboro, Pa, acorporation of Pennsylvania Filed Oct. 11, 1954, Ser. No. 461,307 6Claims. (Cl. 137-501) The present invention relates ,to automatic orself-operated flow-controllers or flow-regulators which may be eithermanually set to any desired flow-rate setting (within the flow-range forWhich the controller is designed by its size and proportions) or whoseflow-rate setting may be effected by an air-motor such as, for instance,a diaphragm or siphon type air-motor, so that the flow-rate setting ofthe flow-controller may be fixed (and varied) from time to timeresponsive to the air-pressure imposed upon the airmotor from someremote control-point; such air pressure being that of any pneumaticcontrol system.

For the purpose of illustrating the invention, there are shown in theaccompanying drawings forms thereof whic are at present preferred,although it is to be understood that the various instrumentalities ofwhich the invention consists can be variously arranged and organized andthat the invention is not limited to the precise arrangements andorganizations of the instrumentalities as herein shown and described.

In the accompanying drawings, in which like reference charactersindicate like parts,

FIGURE 1 represents a perspective view of a manuallyset flow-controllerof the present invention with the inlet at the bottom and the outlet atthe top, as it would be installed in a vertical pipe-line.

FIGURE 2 represents a side elevational view of the aforesaidflow-controller disposed as it would be mounted in a horizontalpipe-line with the dial and manual-setting knob and dial facingupwardly.

FIGURE 3 represents a section on line 33 of FIG- URE 1 but with theflow-controller disposed as in FIG- URE 2, with only the housing insection.

FIGURE 4 represents a section similar to that shown in FIGURE 3, butwith all parts fully sectioned.

FIGURE 5 represents an end elevational view on line 55 .of FIGURE 4.

FIGURE 6 represents a vertical cross-sectional view, similar to thatshown in FIGURES 3 and 4, of an airmotored flow-controller of thepresent invention of the type in which the air-pressure closes thegoverning orifice in the fiow-controller of the present invention.

FIGURE 7 represents a fragmentary cross-sectional view, similar to thatshown in FlGURE 6, but of the airrmotored flow-contnoller ofthe type inwhich the air-pres sure opens the governing orifice.

FIGURE 8 represents a perspective view, partly in section, of theorifice-governing sleeve of the form of construction shown in FIGURE '7.

FIGURE 9 represents a bottom view of the sleeve shown in FIGURES 7 and8.

In one embodiment, the flow-controller of the present invention ismanually set or adjusted to the selected flow-rate, as, for instance theembodiment illustrated in FIGURES 1 to 5, inclusive, while in'anotherembodiment, the flow-controller of the present-invention may be set oradjusted to a desired flow-rate from a remote point, by a pneumaticmotor or pneumatic-actuator or operator, whose pneumatic input isderived from some remote control point.

In both embodiments, however, the main elements of the controller aregenerally the same, as will be seen from the following description andthe accompanying drawings.

In the manually set flow-controller of the present invention, as Well asin the remote-set embodiment of the Ice present invention, thecontroller includes a main body 1i having an inlet 11, an inlet chamber12, a flow-controlvalve chamber 13 communicating with the inlet chamber.12 through the threaded passageway 14, an orifice-valve chamber 15 indirect communication with the flow-controlvalve chamber 13, a stationaryorifice-forming opening 16 on the down-stream side of the orifice-valvechamber 15, opening into the down-stream or discharge chamber 17, whichin turn communicates with the down-stream or discharge-port or threadedopening 13.

A spring-chamber 19 is formed in the main body 10 of the controller, indirect communication with the flowcontrol-valve chamber 13. The outerend of spring-chamher 19 is closed by a closure plate or cap-plate 20which is bolted to the flange 21 of the housing '10 :by means of fourbolts 22 extending through four holes 23 in the capplate 2% and beingthreaded into corresponding threadedopenings 24 in flange 21 of thehousing 10. An annular ringreceiving groove '25 is fiormed either in theface of the flange 21 or in the juxtaposed face of the closure-cap 2t,and into this ring-receiving groove, an O-ring type packing or sealingring 26- is placed, of suitable dimension, so that it is adequatelycompressed when the cap 2% is screwed tightly against the flange 21, soas to form a fluid-seal bet-ween the flange 2.1 and the cap 20.

A threaded hole 27 may be formed in the cap 20, which is normally closedby a screw-threaded drain-plug 28 (FIGURE 6). This opening may be usedto drain the fiow controller of liquid whenever necessary, or may beotherwise used.

A communicating passageway 29 is formed in the wall intervening thedown-stream chamber 17 and the springchamber 19, so as to maintain apermanent and free comununication between these two chambers.

A stationary valve-sleeve 3d open at its up-stream and closed at itsdown-stream end .and haying a series of circumferentially distributedoutlet ports 31 extending radially therethrough near the closeddown-stream end thereof, is screw-threadedly (or otherwise) stationarilymounted in the passageway 14, in axial alignment with the generallycylindrical spring-chamber 19; said sleeve fill having a stop-flange 32serving to fix its position, axially, in relation to the passageway 14,and serving as a stop, to limit the motion of the movable valve-sleeve33, which is slidably mounted on the stationary-valve-sleeve 30.

The movable valve-sleeve 33 is provided with acorresponding number oflantern-shaped valve-ports 3 4, which coact with the stationary ports31, to regulate the flow through the flow-controller; together forming aflowthrottling valve.

Within the up-stream end of the spring-chamber 19 a cylindrical sleeve35 is mounted, and held in place, against the slight inturn flange 36 ofthe housing, either by means of an adjustable post 37 screw-threadedlymounted in the cap 2t), as at 38, or the sleeve 35 maybe held in placeby providing an annular groove in the wall of the springchamber 19immediately adjacent to the down-stream end of the sleeve 3i and placinginto such groove an outwardly expanding split annular retainer-ring ofspring metal, the inner periphery of which ring will overlap thedown-stream end of the sleeve 35 sufficiently to bar its axial movementwithin the spring-chamber 19.

To the lower or down-stream end of the movable valvesleeve 33, a flange39 is secured (by being screw-threaded thereto or otherwise sectu'edthereto). To the flange 39 a piston-like disc 40, flat annulus shaped,is loosely secured, that is, so that it can adjust readily in radialdirections, in relation to the flange 39 by being held between thedoWn-stream side of the flange 39 and the cup-shaped spring-abutmentwasher or plate 41; the springabutment plate 41 and the flange 39 beingheld together by a series of counterpoints 42, or the like, extendingthrough corresponding apertures in the flange 39 and plate 41, withinthe inner diameter of the annulus shaped disc 49.

Two generally co-axially disposed and nested helical compression springs43 and 44 are interposed between the cap and the spring-seat plate 41.The outer spring is held in coaxial relationship at its outer end by thecylindrical wall 45 of the spring-recess in the cap 20, While at itsinner end it is generally centered by the cylindrical flange of thespring-seat 41. The inner spring 43 is centered by the cylindrical wall46 of the inner springseating recess in the cap 20, while its outer endis centered by the cylindrical extension of the plate 39 (as shown inFIGURE 4).

Within the cylindrical orifice-valve chamber 15 a generally cylindricalrotatable sleeve-shaped orifice-valve 47 is disposed. The inner end ofthis tubular or sleeveshaped orifice-valve is open, while its outer endis closed and is riveted or otherwise permanently secured to thereduced-diameter portion 48 of the valve stem 49, preferably with ametal washer 50 intervening the fiat closed end of the valve-sleeve 47and the shoulder interveing the reduced-diametered portion 48 of thevalve-stem and the main valve-stem 49.

Valve-stem 49 passes through the co-axial opening 51 in the bushing 52,which is screw-threaded into the opening 53 of the housing 10,co-axially in relation to the orifice-valve chamber 15. An annularring-receiving recess 54 is provided in the inner end of the bushing anda similar annular ring-receiving recess 55 is provided in the housing,at the outer end of the threaded opening 53, and into these recessessimilar O-rings 56 and 57, of suitable size, are placed for effecting aseal between the valve-stem 39 and the bore 51 of the bushing 52, andfor efiecting a similar fluid-tight seal between the bushing 52 and thehousing 10.

The housing 10 is provided with two or four lugs 58, spaced from eachother as at the four corners of a square, and these lugs are providedwith threaded opening 59, for the reception of mounting screws 60, bywhich the controller may be mounted on any suitable instrumentpanel orother panel 61. The panel 61 may be vertical, horizontal or may beotherwise disposed. By this means the controller may be mounted in anyposition on the panel. Thus, for instance, when mounted on a verticalpanel, it may be so mounted that the axis of the inlet and outletopenings 11 and 18 is horizontal, or so that said axis is vertical or inany position between horizontal and vertical, and with either inlet oroutlet facing in either direction. The dial 62 may then be secured bymeans of screws 63, so as to place the scale 64 thereof in any directiondesired.

To the outer end of the valve-stem 49 a handle or knob 65, having apointer 66, is secured by a set screw 67 or the like. The centralopening 68 in the dial-plate 62 is provided with an enlargement throughone half of the circle, as at 69, in which the stop-pin 70 may movethrough approximately 180, to correspond with the scale 64; the ends ofthe enlargement 69 serving as stops, to limit the pin 70 and hence theknob 65 to 180 motion.

The orifice-valve-sleeve 47, is provided with a sideopening 71 therein,extending through approximately 180 around the cylindrical sleeve 47;one edge, preferably the lower edge 72 of said opening being horizontalwhile the other edge 73 is at an incline, so that the turning of thesleeve 47, is relation to the stationary orifice-opening 16, will varythe area of the opening 16 which is uncovered by the solid portions ofthe sleeve and which is thus placed in communication with the opening 71of the sleeve. Thus, the effective area of the orifice is varied betweenthe inclined edge 73 of the opening 71 and the edge of the fixedorifice-opening 16.

The liquid entering through the inlet-opening 11 passes into thestationary valve-sleeve 30, in the direction of the arrows 74, andradially out through the variably registering openings 31 and 34, in thedirection of the arrow 75, and thence into the open end of the sleeve 47and through the orifice created between the edge of the openings 16 andthe edge 73 of the sleeve-opening 71, in the direction of the arrow 76and thence out through the outlet-opening 18.

The orifice, created as aforementioned, between the inclined edge 73 andthe edge of the opening 16, serves to create a pressure-drop, so thatthe pressure on the upstream side of such orifice (namely inside thesleeve 47 and in the chamber 13) is higher than the pressure on thedown-stream side of the said orifice (namely than in the chamber 17).

As the down-stream side of the orifice, namely, the chamber 17, is infree communication with the springchamber 19 (through the passageway 29,therefore a pressure-differential is maintained on the opposite sides ofthe disc 49. This pressure-differential tends to move the disc 45}against the force of the springs 43 and 44, and thus move thelantern-ported valve-sleeve 33 in the direction of the arrow 77. As thesleeve 33 is moved in the direction of the arrow 77, the lantern-shapedvalveports 34 go more and more out of registration with the stationaryports 31, so as to tend to reduce the flow through said ports. As theflow reduces, the pressuredrop across the aforementioned orifice alsoreduces and hence the pressure-differential on the opposite sides of thedisc 40 is likewise reduced, and the springs tend to move the sleeve 33into the position where the ports 31 and 34 will be more fully inregistration with each other and thus permit greater flow.

In this way a balance is maintained, and hence a constant flow ismaintained.

By turning the sleeve 47, by the knob 65, the controller may be set toany flow within the maximum and minimum of its range, which maypreferably be indicated on the scale 64 as a percent of the capacity ofthe system.

In the embodiment shown in FIGURES 6 to 9 inclusive, the panel 61 andthe bushing 52 are removed (along with the dial-plate 62 and knob 65)and the Valve-stem 49 and valve-sleeve 47 are likewise removed, and intheir place a bushing 80 is threaded into the opening 53 as shown inFIGURES 6 and 7. The bushing 80 serves as a stufiing gland and alsomotor-mounting. Thus, between the shoulder 81 of the bushing and the nut82, threaded onto the external threads of its reduced-diametered portion83, the ring 84 of the motor-supporting yoke 85 is secured. Upon themotor-yoke 85 any conventional pneumatic-actuator 86 is carried. In theparticular embodiment shown, the actuator is a diaphragm type air-motoror pneumatic actuator, in which a corrugated diaphragm 87 (or sylphontube) is sealingly secured between the flanges 88 and 89 of the twohalves 90 and 91 of the housing, with the valve stem 92 connected, atits outer end, to the movable pneumatic actuator-element, so that airpressure (or vacuum) applied to the inlet opening 93 of the actuator 86will move the valvestem 92 in one direction or the other; theair-pressure or vacuum being counter-balanced or opposed by a suitablespring (not shown) within the actuator 86.

The valve-stem 92 passes through the stufiing-gland-nut 94, and throughthe packing-rings 95 and 96, into the orifice-valve-chamber 15. To theinner end of the valvestem 92, a generally cup-shaped orifice-valve 97or 93 is secured, by screw or riveting. If it is intended to maintain agreater flow with a lower air-pressure applied to the pneumatic actuator86 (or to reduce the orifice at 16 with increase of such air pressure)then the orifice-valve 97 is used, which is a cylindrical member whoseinner edge coacts with the lower edge of the opening 16, as in FIGURE 6,while if it is desired to increase the flow with an increase ofair-pressure applied to the pneumatic actuator 86 (or to increase theorifice at 16 with increase in air-pressure) then the orifice-valve 98(shown in FIG- URES 7 to 9) is used. The orifice-valve 98 is alsocupshaped but with its open end at the top (instead of its open endbeing at the bottom as in FIGURE 6) and with a series of openings 99 inits otherwise closed bottom, and the axial dimension of its cylindricalportion is substantially greater than the diameter of the opening 16, sothat it can fully close said opening, and so that the uncovering of saidopening is achieved by moving the orifice-valve 98 downwardly (in FIGURE7), as contradistinction to the valve 97 which does not ever have tofully cover the opening 16 but merely to pass its lower edge, in orderto shut off the whole flow.

A linear scale 100 is mounted on the yoke 85 of the pneumatic actuator86, and the thin-edged indicator-disc or pointer 101 is mounted on thevalve-stem 92, in proper juxtaposition to the scale 1% to indicate thepercent of the flow-capacity to which the controller is set at any time(by the pneumatic pressure).

To provide lubrication between the packing-rings 5 and the valve-stem92, the metallic ring 96 may be interposed between the non-metallicrings 95 above and below the metallic ring (or other hard ring 56) beingprovided with an annular groove on the outside and with a series ofradial openings therethrough, for the passage of lubrication. At a pointin alignment with said ring 96, a threaded opening is provided in thebushing 80, into which any suitable lubricator 102 which may bescrewthreadedly secured.

In the flow-controller of the present invention, an intermediatepressure is maintained on the up-stream side of the orifice (formedbetween opening 16 and the orificevalve 47, 97 or 58). This intermediatepressure is generally equal to the up-stream pressure of the liquid plusthe relatively constant pressure supplied by the springs 43 and 44; thelatter pressure being equal to the total force of said springs dividedby the area of the disc 4-0.

The inlet (through the variably-registering ports 31 and 34) isthrottled responsive to the pressure-differential across the orificeformed between the stationary opening 16 and the orifice-valve (47, 97or 98).

The setting of the orifice-valve (47, 97 or 98) determines the fiow-ratewhich is maintained by the controller.

The up-stream pressure of the fluid (in the inlet chamber 12) isbalanced by the down-stream pressure in the chamber 17 plus thespring-pressure (created by the springs 43 and 44).

A constant pressure-differential is maintained across the orifice formedby the opening 16 and the orifice-valve 47, 97 or 98. This results in aconstant flow-rate. This constant flow-rate will be maintained unlessand until the setting of the orifice-valve 47, 97 or 98 is changed (bythe knob 65 or by the pneumatic actuator 86).

As the controller of the present invention does not depend on anygravity-loading or weight-loading means, it may be installed with theflow to right or left, upward or downward, or in any other direction.Connections are straight, namely, in-line; no off-setting being requiredbetween inlet pipe and outlet pipe connected to the controller.

Panel-mounting, with dial and knob in front, and with controller andother mechanism being in the rear of the panel is also provided by thepresent construction. When the controller is not mounted on a panel, butmerely held in place by the pipes connected to its inlet and outlet,then the panel 61 is replaced by the plate 61-11 which acts as a fillerto which the dial-plate 62 is secured.

In place of the post or pin 37, to restrain and hold in position thesleeve 35, as shown in FIGURE 4, the split annular andoutwardly-expanding spring-ring 163 may be used, within the annularring-receiving groove 104 in the wall of the spring-chamber 19; thegroove 104 having approximately a semi-circular cross-section.

To keep the knob 65 clear of the dial-plate 62, a helical compressionspring 155 may be interposed between the bushing 52 (or the washer 106thereon), and the underside of the knob 65, as shown in FIGURE 4.

Thus, the flow-controller of the present invention includes agoverning-orifice, as, for instance, that formed between the stationaryorifice-opening 16 and the cooperating edge of the orifice-valve (47, 97or 98); which governing-orifice is set to any of its positions, withinits setting-range, either manually or by a pneumatic actuator or similaractuator, and also includes a flow-throttling orifice or valveintermediate the inlet 12 and such governing-orifice (theflow-throttling orifice or valve being formed of the stationaryvalve-sleeve 30 and the movable valve-sleeve 33, with thevariably-registering ports 31 and 34 thereof).

The flow-controller of the present invention also includes asetting-mechanism or throttling actuator for the flow-throttling valve,which setting-mechanism includes a movable piston-like member whose oneside is exposed to the intermediate-pressure (namely, the pressurebetween the flow-throttling valve and the governing-orifice), and whoseother side is exposed to the down-stream pressure on the down-streamside of the governing-orifice, plus the pressure of the spring orsprings; such mechanism being connected to the movable valve-element ofthe flow-throttling valve or orifice.

By using two springs, relatively heavy, the possibility of the disc 40and hence the valve-sleeve 33 acquiring a resonant-frequency buzz isminimized.

The present invention may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof, and it istherefore desired that the present embodiments be considered in allrespects as illustrative and not restrictive, reference being had to theappended claims rather than to the foregoing description to indicate thescope of the invention.

Having described the invention, the following is claimed:

1. A flow-controller including an inlet chamber having an inlet openingadapted to be connected to the up-stream side of a pipe-line and anoutlet chamber having an outlet opening adapted to be connected to adown-stream side of a pipe-line, a flow-throttling valve-chamberadjacent said inlet chamber, a passageway between said inlet chamber andsaid flow-throttling valve-chamber, a stationary Valvesleeve affixed insaid passageway with its fixed end (in said passageway) being incommunication with said inlet chamber, said stationary valve-sleevehaving a port means extending radially thereof in the portion thereofwhich is within said flow-throttling valve-chamber, a piston-re ceivingcylinder-chamber immediately adjacent to said flow-throttlingvalve-chamber and formed in continuation thereof, a piston reciprocablymounted in said cylinderchamber, a movable valve-sleeve carried by saidpiston and having radial ports therethrough, said movable valvesleeveand the aforementioned stationary valve-sleeve being telescoped inrelation to each other, with their respective ports in registration witheach other when said movable valve-sleeve and said stationaryvalve-sleeve are in their maximum telescoped relation to each other, andsaid ports gradually going out of registration with each other when saidmovable valve-sleeve is withdrawn in relation to said stationaryvalve-sleeve in the direction of said piston, a spring in saidcylinder-chamber urging said piston and said movable valve-sleeve in thedirection of said stationary valve-sleeve, a passageway intermediatesaid outlet chamber and said cylinder-chamber on the spring side of saidpiston, a cylindrical governing-orifice chamber in free communicationwith said flow-throttling valve-chamber, a fixed port-like passagewayintermediate said governing-orifice chamber and said outlet chamber, acylindrical movable orifice-governing valve-member within saidgoverning-orifice chamber and fitting therewithin and movable therein inrelation to said port-like passageway, to form with the latter avariable orifice when moved and positioned in relation thereto, a stemfixed to said cylindrical movable orifice-governing valve-member andextending exteriorly of said flow-controller whereby said valve-membermay be positioned in any desired position in relation to said port-likeorifice-forming passageway.

2. A flow-controller in accordance with claim 1 in which theorifice-governing valve-member is a sleeve revolvably mounted Withinsaid governing-orifice valvechamber and is open at its end which facesthe flowthrottling valve-chamber and has at least one inclinedorifice-forming edge in juxtaposition to said port-like passageway, sothat the turning of said orifice-governing valve-member and the settingthereof in any desired position will form a variable orifice of desiredmagnitude be tween said inclined edge and the edge of said port-likepassageway.

3. A flow-controller according to claim 2 in which a stufling-gland isprovided around the stern of said orificegoverning valve-member and inwhich a dial is afiixed to the housing of said flow-controller at aright angle to said stem, through which said stem extends, and in whicha manually operable handle is afi rxed to the outer end of said stemwith a pointer thereon in juxtaposition to said dial.

4. A flow-controller according to claim 1 in which saidorifice-governing valve-member is a reciprocable piston having an edgeforming an orifice with an edge of said port-like passageway.

5. A flow-controller according to claim 4 in which an air motor isconnected to the stem of said orifice-governing valve-member, thehousing of said air motor afiixed to the housing of saidflow-controller.

6. An automatic pressure-responsive valve for use with flow-restrictingorifice in a pipe-line to control the flow of fluid therethrough, andadapted to be mounted in such pipe-line up-strcam of said orifice, saidautomatic valve including an inlet chamber having an inlet openingadapted to be connected to the up-stream side of said pipeline withrespect to said orifice and an outlet chamber having an outlet openingadapted to be connected to the upstream side of said orifice, aflow-throttling valve-chamber adjacent said inlet chamber, a passagewaybetween said inlet chamber and said flow-throttling valve-chamber, a

stationary valve-sleeve affixed in said passageway with its fixed end(in said passageway) being in communication with said inlet chamber,said stationary valve-sleeve having'port means extending radiallythereof in the portion thereof which is within said flow-throttlingvalve-chamber, a piston-receiving cylinder-chamber immediately adjacentto said flow-throttling valve-chamber and formed in continuationthereof, said piston-receiving cylinder-chamber being adapted to becommunicatively connected with said pipe-line down-stream of saidorifice, a piston reciprocably mounted in said cylinder-chamber, amovable valve-sleeve carried by said piston and having radial portsthere through, said movable valve-sleeve and the aforementionedstationary valve-sleeve being telescoped in relation to each other, withtheir respective ports in registration with each other when said movablevalve-sleeve and said stationary valve-sleeve are in their maximumtelescoped relation to each other, and said ports gradually going out ofregistration with each other when said movable valvesleeve is withdrawnin relation to said stationary valvesleeve in the direction of saidpiston, and a spring in said cylinder-chamber urging said piston andsaid movable valve-sleeve in the direction of said stationaryvalve-sleeve.

References Cited in the file of this patent UNITED STATES PATENTS1,132,095 Hutchison Mar. 16, 1915 1,397,867 Jones Nov. 22, 19212,272,684 Vickers Feb. 10, 1942 2,476,720 Gardiner July 19, 19492,608,209 Bryant Aug. 26, 1952 2,645,885 Benua July 21, 1953 2,664,102Coberly Dec. 29, 1953 2,674,847 Davies Apr. 13, 1954 2,702,050 ThomasFeb. 15, 1955 FOREIGN PATENTS 896,214 France Apr. 24, 1944

1. A FLOW-CONTROLLER INCLUDING AN INLET CHAMBER HAVING AN INLET OPENINGADAPTED TO BE CONNECTED TO THE UP-STREAM SIDE OF A PIPE-LINE AND ANOUTLET CHAMBER HAVING AN OUTLET OPENING ADAPTED TO BE CONNECTED TO ADOWN-STREAM SIDE OF A PIPE-LINE, A FLOW-THROTTLING VALVE-CHAMBERADJACENT SAID INLET CHAMBER, A PASSAGEWAY BETWEEN SAID INLET CHAMBER ANDSAID FLOW-THROTTLING VALVE-CHAMBER, A STATIONARY VALVESLEEVE AFFIXED INSAID PASSAGEWAY WITH ITS FIXED END (IN SAID PASSAGEWAY) BEING INCOMMUNICATION WITH SAID INLET CHAMBER, SAID STATIONARY VALVE-SLEEVEHAVING A PORT MEANS EXTENDING RADIALLY THEREOF IN THE PORTION THEREOFWHICH IS WITHIN SAID FLOW-THROTTLING VALVE-CHAMBER, A PISTON-RECEIVINGCYLINDER-CHAMBER IMMEDIATELY ADJACENT TO SAID FLOW-THROTTLINGVALVE-CHAMBER AND FORMED IN CONTINUATION THEREOF, A PISTON RECIPROCABLYMOUNTED IN SAID CYLINDERCHAMBER, A MOVABLE VALVE-SLEEVE CARRIED BY SAIDPISTON AND HAVING RADIAL PORTS THERETHROUGH, SAID MOVABLE VALVESLEEVEAND THE AFOREMENTIONED STATIONARY VALVE-SLEEVE BEING TELESCOPED INRELATION TO EACH OTHER, WITH THEIR RESPECTIVE PORTS IN REGISTRATION WITHEACH OTHER WHEN SAID MOVABLE VALVE-SLEEVE AND SAID STATIONARYVALVE-SLEEVE ARE IN THEIR MAXIMUM TELESCOPED RELATION TO EACH OTHER, ANDSAID PORTS GRADUALLY GOING OUT OF REGISTRATION WITH EACH